1. Field of the Invention
The invention relates to assembly and alignment of multiple optical fibers. More particularly, the invention relates to assembly apparatus and methods for aligning optical fibers for connectorization.
2. Description of the Related Art
The explosive growth in demand for capacity in communications networks including data networks has spawned an increase in the number of optical fibers within optical fiber cables and in the attendant interconnections between the optical fiber cables and the network nodes. Also, the increasing use of optical fibers for shorter-haul distances has further prompted a need for optical cables with larger fiber counts. Such short-haul uses include local loop applications and delivery of communication services to homes and offices. Because of these increased demands placed on optical fiber communication systems, the organization and alignment of optical fibers, e.g., for interconnection between various optical devices, has become more important to the overall performance of the optical system.
Typically, optical fibers are organized into ribbon cables or other arrangements having highly precise, fixed spatial relationships. An optical fiber ribbon or ribbon cable includes a plurality of optical fibers that extend longitudinally and are laterally adjacent and bound together laterally by a matrix material as a single, linear array of optical fibers. Optical fiber ribbon cables typically are connected to other optical devices such as optical transmitters, receivers or other optical fibers through one or more optical connectors.
Optical fiber ribbon connectors typically include a metal or silicon body having an array of grooves dimensioned to position the ends of the individual optical fibers within the ribbon cable. More recently, such connectors have been made of plastic. Typically, the individual fibers are stripped of their protective coating and secured side by side in the connector grooves. The fibers ends then are cleaved and polished to form a smooth surface with the connector endface. The ribbon cable typically is connected to other optical devices by butt-splicing the connector endface to a similar surface of the other optical device. In this manner, the use of ribbon fiber for multi-fiber interconnection simplifies the connection arrangements, provides fiber strength and stability and improves the consistency of the spacing between adjacent fibers.
However, in applications where the optical fibers to be interconnected have different arrangements or are sized differently, conventional interconnection devices and methods are insufficient. For example, in optical fan-in/fan-out arrangements, the fan-in side typically is characterized by uniform spacing between one or more linear arrays of optical connections, e.g., a ribbon fiber arrangement. In contrast, the fan-out side typically is characterized by a plurality of multi-pitched fibers that often are of varying size or are sized differently than the fibers of the fan-in side, which often are sized and spaced in accordance with conventional, commercial connectors. Quite often, the fan-out side has a plurality of individual optical fibers connected thereto. Thus, interconnection between the two disparate arrangements requires an effective alignment transition therebetween.
Accordingly, it would be desirable to have available interconnection apparatus and/or methods for transitioning between different optical fiber arrangements. In this manner, optical fiber arrangements such as optical ribbon cables are suitable for connection to optical devices such as optical transmitters, optical receivers or are interconnected to other optical fibers, regardless of whether such fibers are in the form of other ribbon cables or multipitch, multi-fiber arrangements typical of, e.g., fan-out configurations.
The invention is embodied in an optical uniform spacing assembly for aligning a multipitch plurality of optical fibers into a uniform pitch linear array of optical fibers. The optical uniform spacing assembly includes an organizer body having a slot formed therein that extends longitudinally along the body. A portion of the slot has a width dimensioned to allow only one optical fiber at a time therethrough simultaneously and a depth dimensioned to align a multipitch plurality of optical fibers into a uniform pitch linear array. That is, a portion of the slot has a width only slightly larger than the diameter of an optical fiber and a depth that is only slightly larger than the width of a uniform linear array of optical fibers.
The spacing assembly provides sufficient alignment for transitioning from, e.g., an optical fan-out arrangement such as a plurality of individual optical fibers to, e.g., an optical fan-in arrangement such as a ribbon cable arrangement. The spacing assembly provides a compact, easily assembled apparatus and method for overcoming size mismatch and other conventional problems associated with transitioning between differing arrangements.
Alternatively, the spacing assembly includes a transition assembly coupled to the front or fan-out end of the organizer for providing additional alignment to, e.g., a multipitch array of optical fibers, prior to their alignment within the organizer body. Also, alternatively, an optical device such as a multifiber optical connector is coupled to the back or fan-in end of the organizer body. Suitable multifiber connectors include, e.g., a MT connector, a MAC connector, or a LMC connector.